i'm sitting here with my friend who is an expert in metal music, and he says the production quality on this is shite. what say you?
As an audio engineer, A&R person, and Metal expert... the production there is fine. I mean, it's acceptable and professional, and unless your friend is regularly producing/engineering records that are being released on Metal Blade or some other label of note... Then you can probably safely tell him to STFU

It's probably not his exact "taste", but mixing an album is very subjective. A lot of metalheads, being intelligent-enough types, fall victim to "armchair quarterback" syndrome. I used to have a job that was screening music demos full time. The production here probably isn't great, but it's not lacking. It get's a lot worse.